Editing Malignancy (section)

==Causes==
Malignant cells often evolve due to a combination of reasons rather than one definitive reason. Reasons which can explain their development include genetics and family history, triggers such as infectious diseases, and exposure to risk factors.

===Triggers===
[[Infectious diseases]] play a role in the development of malignancy, with agents of infectious disease being able to produce a multitude of malignant cells.<ref name = "Callahan_1999">{{cite journal | vauthors = Callahan CM, Vincent AL, Greene JN, Sandin RL | title = Infectious Causes of Malignancy | journal = Cancer Control | volume = 6 | issue = 3 | pages = 294–300 | date = May 1999 | pmid = 10758560 | doi = 10.1177/107327489900600314 | doi-access = free }}</ref> These include bacterial causes, fungal and parasitic causes and, viral causes.<ref name = "Callahan_1999" /> [[Bacteria]], [[fungi]] and similar [[pathogens]] have the ability to form an environment within states of chronic inflammation which gives rise to oncogenic potential.<ref name = "Callahan_1999" /> Viral agents are able to assist the formation of malignant tumours due to a mechanism of cell transformation.<ref name = "Callahan_1999" /> This cell transformation can occur through either "DNA integration or cellular-DNA alteration of growth regulator genes".<ref name = "Callahan_1999" /> [[Inflammation]] can also play a role in triggering malignancy as it can promote stages of tumour formation.<ref name = "Greten_2019">{{cite journal | vauthors = Greten FR, Grivennikov SI | title = Inflammation and Cancer: Triggers, Mechanisms, and Consequences | journal = Immunity | volume = 51 | issue = 1 | pages = 27–41 | date = July 2019 | pmid = 31315034 | pmc = 6831096 | doi = 10.1016/j.immuni.2019.06.025 }}</ref> The main purpose of inflammation is to repair tissue, defend the body against pathogens and regenerate cells.<ref name = "Greten_2019" /> At the same time, inflammatory cells can also interact with malignant cells to form an inflammatory tumour [[Microenvironment (biology)|microenvironment]].<ref name = "Greten_2019" /> This environment increases the likelihood of forming malignant cells through blockage of anti-tumour immunity.<ref name = "Greten_2019" /> Once this occurs, the inflammatory tumour microenvironment begins to send out tumour-promoting signals to [[epithelial]] cells, triggering the formation of malignant cells.<ref name = "Greten_2019" />

===Risk factors===
Traditional risk factors of developing malignancy include smoking, sun exposure and, having a history of cancer in the family. Other risk factors include developing post-transplant malignancy which occurs subsequent to solid [[organ transplantation]]s.<ref name = "Rossi_2018">{{cite journal | vauthors = Rossi AP, Klein CL | title = Posttransplant Malignancy | journal = The Surgical Clinics of North America | volume = 99 | issue = 1 | pages = 49–64 | date = February 2019 | pmid = 30471741 | doi = 10.1016/j.suc.2018.09.004 | s2cid = 53756320 }}</ref>

====Post-transplant malignancy====
Individuals who undergo organ transplant surgery have an increased risk of developing malignancy in comparison to the general population.<ref name = "Rossi_2018" /> The most common form of malignancy being "[[nonmelanoma skin cancer]] and, posttransplant [[lymphoproliferative disorders]]".<ref name = "Rossi_2018" /> The different types of malignancy developed post-transplant depend on which organ was transplanted.<ref name = "Collett_2010">{{cite journal | vauthors = Collett D, Mumford L, Banner NR, Neuberger J, Watson C | title = Comparison of the incidence of malignancy in recipients of different types of organ: a UK Registry audit | journal = American Journal of Transplantation | volume = 10 | issue = 8 | pages = 1889–1896 | date = August 2010 | pmid = 20659094 | doi = 10.1111/j.1600-6143.2010.03181.x | s2cid = 40192165 | doi-access = free }}</ref> This is linked to recipients being at a higher risk when exposed to traditional risk factors as well as, the type and intensity of the operation, the duration of their [[immunosuppression]] post-operation and, the risk of developing oncogenic viral infections.<ref name = "Rossi_2018" />